1. Acknowledge the problem without acknowledging specifics. This was our very first tweet:

@BPGlobalPR: We regretfully admit that something has happened off of the Gulf Coast. More to come.

2. Be open about one piece of bad news and no more. You want to appear human, but you don't want to appear like a bunch of idiots. There's another word I'd use there, but I don't think I can. It rhymes with mickleticks.